Valve for air mattress



June 18, 1968 Filed NOV. 12, 1965 P. SCHREIBER ETAL VALVE FOR AIR MATTRESS 5 Sheets-Sheet 1 INVENTORJ ATTORNE'YJ June 18, 1968 P, scHRElBER ET AL 3,388,701

VALVE FOR AIR MATTRESS Filed Nov. 12, 1965 3 Sheets-Sheet 2 Peter Schrez'ber Hans Geory Brei/iy mi? arrow a June 18, 1968 P C R R ET AL 3,388,701

VALVE FOR AIR MATTRESS Filed Nov. 12, 1965 3 Sheets-Sheet 5 INVENTORS Peter- Schr'ez'ber' Hans Geor Bred/0'37 7? J iwom w United States Patent "ice 3,388,701 VALVE FUR AIR MATTRESS Peter Schreiber and Hans Georg Breiling, Lubcck, Germany, assignors to Otto H. Drager, Lubeck, Sci-many Filed Nov. 12, 1965, Ser. No. 507,478 Qlaims priority, application Germany, Dec. 24, 1964,

9 Claims. oi. 12s-s3 ABSTRACT OF THE DISCLOSURE This invention relates to an air mattress and especially to a valve for alternately inflating and deflating separate groups of air cells in the mattress.

Alternating pressure air mattresses are known which contain groups of air cells separate from each other and which are in a predetermined pattern, such as alternately inflated with air and deflated. The body of the patient lying on the mattress consequently is not always in contact with the mattress with the same parts of his body. This means that it is possible to position the patients body on the mattress with respect to the position of the air cells in the mattress and which air cells are to be infiated. Thus the load of each particular portion of the body can be taken off at least for a short period of time so as to maintain a uniform circulation of blood through the body and the skin so as to prevent bed sores (decubitus ulcers). The mattress can contain two or more separate groups of air cells. In a simple form of the invention, only two groups of cells are used which are separate from each other. The groups of air cells, of course, can be evenly distributed across the mattress or arranged in any suitable manner.

Either motor or manually actuated pumps can be used to alternately fill the groups of air cells adjacent each other and such pumps are operated to uniformly supply air for alternately inflating or deflating the air from the air cells.

Apparatuses have been used in which two groups of air cells are connected to opposite sides of an electrically driven dual purpose air pump.

Also known are mattresses having alternately pressured air cells connected to a pressurized gas source in such a way that the inflation as well as the deflation of the cells is controlled by a valve. The necessary maximum pressure is set by a relief valve. The apparatus in one construction of this type has each group of air cells connected to a dual purpose valve so that, when the valve is in one position, a group of air cells communicates with the source of pressure, and when the valve is in another position, the air cells communicate with the surrounding atmosphere. Magnetic valves have been used for this purpose which may be electrically controlled by the air in a control cylinder.

In such known mattresses with alternately pressurized air cells, the disadvantage exists that, as one group of air cells is inflated, the adjacent group of air cells is already in the process of deflation. Thus, as the pressure is changed in the groups of cells, the patient is alternately lowered and lifted. Furthermore, with electrically controlled valves, 9. further disadvantage lies in that the 3,3833% Patented Jame 18, 1968 change in air pressure cannot take place during a power failure. Also, electrically driven control means are not permitted in certain hospitals.

The object of this invention is to avoid the above disadvantages of the prior art systems. This invention is an improvement over a mattress air cell system whose air cells are connected by two valves which alternately open and close with respect to the source of pressurized gas and with respect to the atmosphere so that the valve openable to the atmosphere is closed When the valve openable to the gas supply is opened and vice versa. In this invention, the valve means is so constructed so that it can be turned to the following four control settings:

(a) Valve open to supply air to a first group of cells while being closed against a supply of gas to a second group of cells;

(b) Valve open to supply air to a first group of cells while being also open to supply air to the second group of cells;

(0) Valve closed against the supply of air to the first group of cells while being opened to supply air to the second group of cells; and

(d) Valve open to supply air to the first group of cells while being also open to supply air to the second group of cells. This is the same as (b) above.

The advantage of this invention is in that the patient always lies at the same level since the pressure in one group of cells does not drop until after the pressure in an adjacent group of cells has been increased to inflate the cells.

A further feature of the invention is in that each group of air cells is connected by a pipe, respectively, with adjacent pump chambers of a control apparatus. A movable wall or a movable partition separating the pump chambers is connected to the valve for rotating or turning the same. This has the advantage in that the need for an electrical control mechanism is avoided.

The means by which the objects of the invention are obtained are described more fully with reference to the accompanying drawings in which:

FIGURE 1 is a diagrammatic cross-sectional view through the valve mechanism of this invention;

FIGURES 2a, 2b, 2c and 2d are schematic views taken on the line 2-2 of FIGURE 1 showing different positions of the valve;

FEGURES 3a, 3b, 3c and 3d are diagrammatic views of different positions for the drive mechanism of the valve; and

FIGURE 4 is a cross-sectional view taken on the line 44 of FIGURE 1.

As shown in FIGURE 1, a pressurized air source 1, such as compresed air, is connected through a pressure regulator 2 to the interior 3 of the valve mechanism.

This valve mechanism has a cylindrical housing 4, one end of which is closed by a valve seat 5 upon which a circular valve head 6 is adapted to slide by rotating or turning on the valve seat. A semi-circular slot 7 extends through valve head 6. Also the side of the valve head seated on the valve seat 5 is provided with a circular segment recess 8.

Valve seat 5 has sir-1 ports extending therethrough which, in a simple manner, are represented as being parallel to the central axis M of valve head 6. The two outermost ports 9 and 16 which are radially equidistant from axis M are connected each, respectively, with one of the groups of air cells 11 and 12 schematically indicated as eing in a mattress. The connecting pipes 13 and 14 are joined through branch pipes 15 and 16 to the ports 17 and 18 also equidistant from axis M. Valve seat 5 is finally provided with ports 19 and 20 which open into the atmosphere and which are also equidistant from axis M. Valve head 6 is joined to a cylindrical drive shaft 21,

only partly shown in section. This shaft has a cam groove 21a in its exterior surface into which is seated a cam pin 22a secured to a cylindrical portion 22 of a drive rod. Portion 22 is telescoped over shaft 21. Valve head 6 is constantly urged by a compression spring 23 against the valve seat with the opposite end of the spring bearing against an abutment 24 mounted within the housing 4.

Cylindrical portion 22 is a part of a drive rod 25 Which extends through the end 26 of housing 4 and also through a head piece 27. An accordion bellows 28 is secured between end 26 and head piece 27 and sealed gas tight. Bellows 28 is separated by a partition 29 and urged to normally centered position by spring 30 and 31 which abut partition 29 and the end 26 and head piece 27, respectively. Bellows 28 is thus separated into two chambers 32 and 34. Chamber 32 is connected by pipe 33 to air cell group 11, while chamber 34 is connected by pipe 35 to air cell group 12 in the mattress. The apparatus operates as follows, it being noted that the position of the apparatus in FIGURE 1 corresponds to the setting of the valve as shown in FIGURE 2a.

Compressed air flows through slot 7 and open port to air cell group 12 in the mattress and inflates that group of cells. At the same time, port 9 is closed by valve head 6. In addition, port 19 communicates with port 17 by reason of being open through recess 8 so that the compressed air in air cell group 11 escapes into the open atmosphere and those air cells are deflated. Furthermore, the compressed air flows through pipes and 35 into bellows chamber 34, while at the same time the bellows chamber 32 communicates with the atmosphere through pipes 33 and 14 and ports 17 and 19. This results in the displacement of rod to the left toward valve head 6 and spring '30 is compressed. This movement causes the cam pin 22a to move in the cam groove 21a, thus turning shaft 21 and valve head 6 so that it is then moved to the position shown in FIGURE 2b. The position of the bellows 28 is that shown in FIGURE 3a.

In the valve position of FIGURE 2b, port 17 is closed and port 9 is open so that the compressed air in the valve interior 3 communicates with the air cell group 11 by way of port 9. Air cell group 11 is therefore inflated with compressed air. Also, in this position, slot 7 remains within the range of port 10 so that air cell group 12 remains filled with compressed air. Therefore, both air cell groups 11 and 12 of the mattress are inflated. However, in this position, compressed air also flows through pipe 33 into bellows chamber 32 of bellows 28 so that finally the pressure is equalized in bellows chambers 32 and 34. Consequently, partition 29 is restored to its center position a by the action of spring and rod 25 and moved to the right in FIGURE 1. This position is represented in FIG- URE 3b and the valve head is moved from the position of FIGURE 2b to that of FIGURE 2c.

In FIGURE 2c, the port 9 communicates through slot 7 with the interior 3 of the valve so that air cell group 11 remains inflated. However, the recess 8 has moved to place ports 18 and 20 into communication. Therefore, the compressed air in air cell group 12 escapes through pipe 16 and ports 18 and 20 into the Outer atmosphere. In the same manner, air escapes from bellows chamber 34 while the pressure in chamber 32 is retained. Partition 29 therefore is moved to the right and pushes rod 25 into the position represented in FIGURE 3c. This movement causes the cam pin 22a to move in the cam groove 21a and turns valve head 6 so that it reaches the position 4 shown in FIGURE 2d by reason of which both the air cell groups 11 and 12 are open through ports 9 and 10 and slot 7 to the interior 3 of the valve and thus both air cell groups are inflated. While one air cell group remains inflated, the other air cell group is being inflated. This equalizes the pressure in bellows chambers 32 and 34 so that the spring 31 moves partition 29 to center position, which is the position as shown in FIGURE 1 and FIG- URE 3b. The valve head has reached its initial position of FIGURE 2a. The procedure is then repeated.

A cylindrical or conical slide valve can be used in place of the valve head 6. Also, a plurality of ports can be substituted for the continuous slot 7.

Having now described the means by which the objects of the invention are obtained.

We claim:

1. An air valve for a mattress having separate groups of air cells adapted to be alternately inflated and deflated by compressed air supplied through the valve, and in which the air supply to a group of cells is closed when the group of cells is open to the atmosphere, comprising a valve head rotatably and slidably mounted on a valve seat, said seat having two ports therein equally spaced from the center of the seat for the supply of air to said cells, and two ports for the passage of air from said cells into the atmosphere; said valve having port means corresponding to the ports in the valve seat for interconnecting the ports in the valve seat, and a recess for establishing communication between the ports for the passage of air from said cells into the atmosphere.

2. An air valve as in claim 1, further comprising two more ports in said seat for the passage of air to said cells.

3. An air valve as in claim 2, said port means in said valve head comprising a circular segment slot.

4. An air valve as in claim 3, further comprising bellows means adapted to be joined to the groups of cell respectively, and drive means for rotating said valve head upon movement of said bellows produce by a pressure dilference between the groups of cells.

5. An air valve as in claim 4, said bellows means comprising two bellows chambers, and pipe means for joining each chamber with its respective group of cells.

6. An air valve as in claim 5, further comprising a partition separating said chambers, and said drive means including a rod connected to said partition for rotating said valve head.

7. An air valve as in claim 6, said drive means further comprising a shaft joined to said valve head, a cam gr ove in said shaft, and a cam pin secured to said rod and seated in said groove.

8. An air valve as in claim 7, said rod further includ ng a cylindrical portion telescoped on said shaft.

9. An air valve as in claim 8, further comprising spring means in said bellows chambers for urging said partition into normally centered position.

References Cited UNITED STATES PATENTS 2,719,986 10/1955 Rand 5---348 3,148,391 9/1964 Whitney 5-348 3,288,133 11/1966 Little 12824 L. W. TRAPP, Primary Examiner. 

